The growth direction of the crystallites of the ferroelectric layer in the capacitor volume is becoming increasingly important with increasing miniaturization of the storage capacitors of ferroelectric data memories (FeRAMs). If the storage capacitor includes only one crystallite, the in-plane orientation of this crystallite is crucial for the switchable polarization and therefore the signal of the corresponding memory cell.
Hitherto, the dimensions of the ferroelectric capacitors have been so large, and therefore contain so many crystallites, that the directional dependency of the polarization has no effect. For two-dimensional capacitors with electrodes parallel to the substrate surface, the influence of this directional dependency, for the case of tetragonal PZT layers, can even been avoided altogether by an <111> texture.